Last frost date in Rock Springs, Wyoming
May 24
Average last frost in spring. In an early year (1 in 10) it's over by May 8; in a late year (1 in 10) it comes after June 9.
September 24
Average first frost in fall. 1 year in 10 it comes by September 9.
Source: NOAA U.S. Climate Normals 1991–2020, station Rock Springs Fire Dept (USC00487847), 1.5 miles from Rock Springs, elevation 6,270 ft. NOAA National Centers for Environmental Information. These are long-term averages, not a forecast.
| Early year | Average | Late year | |
|---|---|---|---|
| Last frost in spring | May 8 | May 24 | June 9 |
| First frost in fall | Sept 9 | Sept 24 | Oct 4 |
Frost-free days in an average year: 121
| Chance in a year | Average last in spring | Average first in fall | |
|---|---|---|---|
| Light frost (36°F) | Every year | June 6 | Sept 14 |
| Frost (32°F) | Every year | May 24 | Sept 24 |
| Hard freeze (28°F) | Every year | May 9 | Oct 3 |
Nights at 32°F or colder in an average year: 184
What to plant now in Rock Springs
- Spring planting calendar for an average last frost around May 20 Rock Springs: May 24
- Fall planting calendar for an average first frost around September 20 Rock Springs: September 24
Planting dates: USDA Home and Garden Bulletin No. 9 (1967), “Suburban and Farm Vegetable Gardens,” tables 4 and 5. How we match the table.
Nearby in Wyoming
- Green River 14 mi · last frost May 24
- Evanston 93 mi · last frost June 12
- Riverton 108 mi · last frost May 12
- Jackson 152 mi · last frost June 20
- Casper 172 mi · last frost May 10
Updated